1. Field of the Invention
The invention relates in general to a method of effacing zipper image, and more particularly, to a method of effacing zipper image by approximating the gray scales of two neighboring pixels.
2. Description of the Related Art
FIG. 1 shows a block diagram of a scanner having a stagger charge-coupled device. In FIG. 1, the scanner 100 is coupled to a computer 150. The scanner comprises a stagger charge-coupled device 110 with a primary line and a secondary line, an application specific integrated circuit (ASIC) 120, an image compensation buffer 130 and an I/O interface 140.
When the scanner having the stagger charge-coupled device is scanning a document, the pitch between the primary line and the secondary line is small. The primary line is thus affected by the light reflected from the secondary line. Similarly, the secondary line is also affected by the light reflected from the primary line. A zipper image (as shown in FIG. 3) in addition to a real image (as shown in FIG. 2) is thus produced by using the scanner with the stagger charge-coupled device to scan the document. When a document has a black-and-white boundary, the zipper image is more obvious, causing error in the actual image. Currently, a method to compensate the zipper image has not been found in the prior art.